1. Field of the Invention
This invention relates to a film processing assembly, and more particularly, to a film chip transport assembly for a film processor automatically processing X-ray film chips.
2. Description of the Prior Art
In U.S. Pat. No. 3,882,525 to Zwettler, there is disclosed a processor for developing batches of dental X-ray film chips including a film transport unit comprised of a pair of laterally-disposed, vertically-spaced, parallel walls forming a continuously curved channel with three loops. The downwardly-extending curved portions of the loops respectively extend into tanks in the development compartment of the processor. A lower lifter is mounted to rotate in each downwardly-extending curved portion of the continuous channel, and an upper lifter is mounted to rotate in each upwardly extending curved portion of the continuous channel. The inside surfaces of the pair of walls are provided with opposing V-grooves which form a path coaxially disposed to the channel for engaging the opposite edges of vertically-disposed film chips. Each film chip is permitted to drop by gravity along the downwardly-extending portions of its path and is lifted by the lower and upper rotating lifters along the upwardly-extending portions of its path.
In U.S. Pat. No. 4,760,417 also to Zwettler, there is disclosed an improved portable roll film processor for automatically processing roll film wherein a removable film drive module is provided for moving the film through tanks containing chemical processing liquids. The film drive module defines an essentially serpentine path for the film including successive "U"-shaped sections depending from a common frame member. Each of the "U"-shaped sections extends into a different tank and includes a down path leg for carrying the film into the tank and an up path leg for carrying the film out of the tank. All moving parts required to move the film are located above the liquids to minimize maintenance problems.
In U.S. Pat. No. 5,241,339 to Maroney and assigned to the same assignee as the present invention, there is disclosed an automatic X-ray film processor assembly comprised of a drive assembly for the film transport unit including intermittently-operated lower lifters for passing the film chips from each tank through succeeding processing units, thereby ensuring more uniform processing time, as well as permitting facile changes in processing times.
While such film processors effectively developed X-ray film chips, the film drive assemblies resulted in variable processing times as well as varying processing conditions, such assemblies rely upon carefully coordinated arm movements. Additionally, the drive assemblies are costly to fabricate.